Devices for cutting hair includes powered hand-held devices that are placed against a user's skin and moved over areas where hair is to be cut. Such devices may include those that use an optical source to remove or sever hairs by photothermolysis, including intense pulsed light, laser beam and any other optical hair removal device and also includes any mechanical hair cutting devices. The user selects which areas of hair to cut and which areas should not be cut by positioning and moving the device appropriately.
Devices for treating hair may include those that treat hair by severing (including by photothermolysis and other optical methods), cutting, trimming, epilating, shaving, applying a substance (for example a colouring agent, shampoo or moisturiser) and others. Such devices are also typically powered hand-held devices and a user selects areas for treatment by positioning and moving the device in the appropriate manner. Similar devices may be used to treat skin, such as a device that applies a cream or other substance to a user's skin for any purpose including moisturising, artificial tanning or for applying a medical substance.
However, such devices are difficult to accurately position on the skin and it is difficult to only treat selected areas of skin and/or hair. The accuracy of the treatment provided by the device depends on the user's skill and steady hand. Moreover, the device and the user's hand and arm may impede the user's view thereby making it difficult to position and move the device accurately. For example, if a facial hair arrangement, such as a goatee beard, were desired then the user would have to position and move a hair cutting device around the shape of the goatee beard, which is difficult to perform and leads to inaccurate or undesired results.